AlmaLinux OS 9 must define default permissions for logon and nonlogon shells.

Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access.

With a UMASK of 077, files will be created with 0600 permissions (owner read/write only) and directories will have 0700 permissions (owner read/write/execute only).

Verify that the "umask" setting for installed shells is "077".

Note: If the value of the "umask" parameter is set to "000", the severity is raised to a CAT I.

$ grep -ir umask /etc/profile* /etc/bashrc* /etc/csh*

/etc/csh.cshrc: umask 077

If the "umask" parameter is set to anything other than "077", this is a finding.

Configure AlmaLinux OS 9 to define default permissions for all authenticated users in such a way that the user can only read and modify their own files.

Change any found "umask" parameters in the "/etc/bashrc*", "/etc/csh*", and "/etc/profile*" files to "077":

umask 077